From 2c2f1a57e6082dba26c05709fd3fa8a6cb38c763 Mon Sep 17 00:00:00 2001
From: Matthew Andres Moreno <mmore500.login+gpg@gmail.com>
Date: Fri, 8 Dec 2023 15:36:47 -0500
Subject: [PATCH] Fixup and test emp::Fraction

---
 include/emp/math/Fraction.hpp | 10 +++---
 tests/math/Fraction.cpp       | 66 +++++++++++++++++++++++++++++++++++
 tests/math/Makefile           |  2 +-
 3 files changed, 72 insertions(+), 6 deletions(-)
 create mode 100644 tests/math/Fraction.cpp

diff --git a/include/emp/math/Fraction.hpp b/include/emp/math/Fraction.hpp
index b84a59d9b9..f427280cf4 100644
--- a/include/emp/math/Fraction.hpp
+++ b/include/emp/math/Fraction.hpp
@@ -13,8 +13,7 @@
 #define EMP_MATH_FRACTION_HPP_INCLUDE
 
 #include <cstdint>
-
-#include "math.hpp"
+#include <numeric>
 
 namespace emp {
 
@@ -23,6 +22,7 @@ namespace emp {
     int64_t num;    // Numerator
     int64_t denom;  // Denominator
 
+  public:
     void Reduce() {
       if (denom == 0) return;                 // Undefined value!
       if (num == 0) { denom = 1; return; }    // Zero value!
@@ -32,16 +32,16 @@ namespace emp {
         denom = -denom;
         num = -num;
       }
-      const uint64_t gcd = emp::GCD(num, denom);
+      const int64_t gcd = std::gcd(num, denom);  // overflows if uint64_t
       num /= gcd;
       denom /= gcd;
     }
-  public:
+
     Fraction(int64_t in_num=0, int64_t in_denom=1) : num(in_num), denom(in_denom) { }
     Fraction(const Fraction &) = default;
 
     int64_t GetNumerator() const { return num; }
-    int64_t GetDenomonator() const { return denom; }
+    int64_t GetDenominator() const { return denom; }
   };
 }
 
diff --git a/tests/math/Fraction.cpp b/tests/math/Fraction.cpp
new file mode 100644
index 0000000000..2223c3faff
--- /dev/null
+++ b/tests/math/Fraction.cpp
@@ -0,0 +1,66 @@
+/*
+ *  This file is part of Empirical, https://github.com/devosoft/Empirical
+ *  Copyright (C) Michigan State University, MIT Software license; see doc/LICENSE.md
+ *  date: 2023
+*/
+/**
+ *  @file
+ */
+
+#include "third-party/Catch/single_include/catch2/catch.hpp"
+
+#include "emp/math/Fraction.hpp"
+
+TEST_CASE("Test Fraction Constructor", "[math]") {
+  emp::Fraction frac1;
+  REQUIRE(frac1.GetNumerator() == 0);
+  REQUIRE(frac1.GetDenominator() == 1);
+  frac1.Reduce();
+  REQUIRE(frac1.GetNumerator() == 0);
+  REQUIRE(frac1.GetDenominator() == 1);
+
+  emp::Fraction frac2(5, 10);
+  REQUIRE(frac2.GetNumerator() == 5);
+  REQUIRE(frac2.GetDenominator() == 10);
+  frac2.Reduce();
+  REQUIRE(frac2.GetNumerator() == 1);
+  REQUIRE(frac2.GetDenominator() == 2);
+
+  emp::Fraction frac3(0, 10);
+  REQUIRE(frac3.GetNumerator() == 0);
+  REQUIRE(frac3.GetDenominator() == 10); // Zero numerator
+  frac3.Reduce();
+  REQUIRE(frac3.GetNumerator() == 0);
+  REQUIRE(frac3.GetDenominator() == 1);
+
+  emp::Fraction frac4(10, -5);
+  REQUIRE(frac4.GetNumerator() == 10); // Negative handling
+  REQUIRE(frac4.GetDenominator() == -5);
+  frac4.Reduce();
+  REQUIRE(frac4.GetNumerator() == -2);
+  REQUIRE(frac4.GetDenominator() == 1);
+
+  emp::Fraction frac5(-10, 5);
+  REQUIRE(frac5.GetNumerator() == -10); // Negative handling
+  REQUIRE(frac5.GetDenominator() == 5);
+  frac5.Reduce();
+  REQUIRE(frac5.GetNumerator() == -2);
+  REQUIRE(frac5.GetDenominator() == 1);
+
+  emp::Fraction frac6(-10, -5);
+  REQUIRE(frac6.GetNumerator() == -10); // Negative handling
+  REQUIRE(frac6.GetDenominator() == -5);
+  frac6.Reduce();
+  REQUIRE(frac6.GetNumerator() == 2);
+  REQUIRE(frac6.GetDenominator() == 1);
+
+}
+
+TEST_CASE("Test Zero Denominator", "[math]") {
+  emp::Fraction frac(10, 0);
+  REQUIRE(frac.GetNumerator() == 10);
+  REQUIRE(frac.GetDenominator() == 0);
+  frac.Reduce();
+  REQUIRE(frac.GetNumerator() == 10);
+  REQUIRE(frac.GetDenominator() == 0); // Expect no change for zero denominator
+}
diff --git a/tests/math/Makefile b/tests/math/Makefile
index 45f7cb1b30..fda1a0daa0 100644
--- a/tests/math/Makefile
+++ b/tests/math/Makefile
@@ -1,4 +1,4 @@
-TEST_NAMES = combos distances Distribution info_theory math random_utils Random sequence_utils spatial_stats stats Range RangeSet
+TEST_NAMES = combos distances Distribution Fraction info_theory math random_utils Random sequence_utils spatial_stats stats Range RangeSet
 
 # -O3	  -Wl,--stack,8388608 -ftrack-macro-expansion=0
 FLAGS = -std=c++20 -g -pthread -Wall -Wno-unused-function -Wno-unused-private-field -I../../include/ -I../../ -I../../third-party/cereal/include/ -DCATCH_CONFIG_MAIN